80% 308 lower/upper combination?

[HPBrowningMK3]

Hey guys,

I am looking for a recommendation based on your experience with lower/upper for 308s. I'd prefer a matched set from the same company, but if that's not doable, I can do a branded upper, no problem.

Thanks!

[Wykyd]

Mega is probably your best bet but spendy

[liber]

LR-308s seem to have more issues than others, since there are so many various uppers and lowers, some of which fit and some that don't. More difficulty in getting the rails lined up with the upper. I have a Parallax FFSSR and bought an Aero Precision M5 upper as I knew it was the correct height.

I've had some problems with it feeding rounds, where it will catch a case shoulder and jam, putting a crease in the case shoulder. A couple weeks ago I was at the range with my LR-308 and had this happen a about one is 20 rounds. Even after the case shoulder was creased, I could put the round back in a mag and I found out it would load just fine. I looked close and was inspecting the M5 upper and was surprised that the machining on the aluminum that mates to the feed ramps on the barrel is not done very well...I was glad to find out what the problem is finally though, and can fix that with a needle file. Such a minor detail, but an annoying one, since as I stated it would jam several times each trip with it to the range.

From what I've read of others putting together LR-308s, this type of small problem is not uncommon. Just an FYI. The LR-308 is an awesome firearm, I really like it a lot, but they are a tad finicky to put together. I've never had an issue on my 5.56s.

[yari]

JL billet makes upper lower combo, and a sexy rail. They are out of San Diego.

[HPBrowningMK3]

@Wykyd, thanks, that's a nice set, no doubt. If I wasn't looking for an 80% DIY, I'd jump on it.

@liber, that's what I've been hearing myself. No issues with 80% AR15 lowers and uppers at all. Do you happen to know which uppers are "higher" and "lower". I am thinking about TM 308 lower and DPMS LR-308 SASS 18". Some people are saying this is a great fit and others are questioning the fit.

[liber]

@liber, that's what I've been hearing myself. No issues with 80% AR15 lowers and uppers at all. Do you happen to know which uppers are "higher" and "lower". I am thinking about TM 308 lower and DPMS LR-308 SASS 18". Some people are saying this is a great fit and others are questioning the fit.

I like the Parallax Free Float Super Slim Rails, they are really nice and just feel nice on the firearm, I have two of them. The only issue with them is that they do use shims to align the rail to the upper correctly, some folks don't care for that. They require the use of a torque wrench with a crowfoot wrench to do correctly, so that may or may not be an issue for some folks.

The Parallax FFSSR 308 rail is high, and so is the Aero Precision. Used to be that most of the DPMS style was high rail, but with the DPMS Gen 2 out there is more low rail stuff on the market it seems. I used a PSA PA-10 upper that I got cheap on sale, but I have only a couple PSA parts left on my rifle. The reason I bought the Aero Precision upper was that the PSA was low rail on the upper. Midwest makes a low rail that will mate with the PSA upper, just that those are about $200, and I got my Parallax (blem) for $125 including shipping. I just put together a 5.56 upper using a 15" Parallax blem I got for $99, hard to beat those prices. Hard to find the blems on them also...Parallax makes good stuff. You can watch their FB page to find out when they run the blem FFSSRs on sale, if you're interested. On my LR-308 I used a Syrac adjustable gas block, it fits in the Parallax FFSSR nicely. The Odin won't fit properly.

I will add that I am a firm believer in buying quality parts. The PSA PA-10 upper was a brainfart when I saw the cheap price. I will replace the barrel with a Criterion in the future. The 5.56 upper I just put together has a Krieger barrel, it's a beauty and I love the upper more than any other upper I have. Check out the Criterion barrels for 308, they look nice.

[FIREBALL_BRIAN]

quentin defense or sundevil mfg

http://quentin-laser.com/store/product_info.php?cPath=27_75&products_id=269

and

http://quentin-laser.com/store/product_info.php?cPath=3&products_id=331

[bauern]

The problem I've encountered most often on mismatched upper and lowers is the rear radius at buffer tube. The slight difference between the two prevents the upper from fully seating and the rear take down pin is difficult to get it.

Take a look at http://shop.elkcreekmanufacturing.co...-308SR2580.htm http://shop.elkcreekmanufacturing.co...iver-308UR.htm for matched upper/lower as well.

[HPBrowningMK3]

Thanks guys, great info.Will report back once I get everything assembled.

Sent from my SM-G900T using Tapatalk

[xfer42]

I have a few of the $95 ares LR308s, with some JSE surplus uppers (not sure who manufactures them). They are tight and dont rattle. The back doesnt match perfectly, but I really didnt notice until today. Still not gonna bother me because you can only see it if you hold it up to a light.

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[Repr762]

Not aure the make of the lower as i bought off a buddy before milling but if fits great on my 12.5 in CMMG Mk3 K "pistol" upper
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[ar15barrels]

I am looking for a recommendation based on your experience with lower/upper for 308s.
I'd prefer a matched set from the same company,

https://genesiscnc.com/product/rifle-builders-set/

[FIREBALL_BRIAN]

randall i must disagree. The link you posted cost too much.

[Nathan Krynn]

@Wykyd, thanks, that's a nice set, no doubt. If I wasn't looking for an 80% DIY, I'd jump on it.

@liber, that's what I've been hearing myself. No issues with 80% AR15 lowers and uppers at all. Do you happen to know which uppers are "higher" and "lower". I am thinking about TM 308 lower and DPMS LR-308 SASS 18". Some people are saying this is a great fit and others are questioning the fit.

Fit should be good, we designed it for the DPMS upper originally. If there are problems please let me know in PM's or email.

[ar15barrels]

80% 308 lower/upper combination?

randall i must disagree. The link you posted cost too much.

It meets the requirements set forth in the original post.
The upper and lower match up perfectly.
They also match up to KAC SR-25 uppers and Larue uppers which can not be said for any of the other 80% 308 lowers out there...